Clinical calculator
LCEA Calculator
Lateral Centre-Edge Angle of Wiberg
The lateral centre-edge angle measures how far the acetabulum covers the femoral head laterally on an anteroposterior pelvis radiograph, where below 18 degrees indicates frank dysplasia, 18 to 25 degrees is borderline, 25 to 39 degrees is normal, and 40 degrees or more indicates overcoverage.
What the LCEA score means
LCEA scores run from 0 to 60, where a higher score is better. The bands below are conventional reporting categories, not diagnostic cut-offs.
- Frank acetabular dysplasia-90–17.9
An LCEA below 18° is widely accepted as frank dysplasia. Undercoverage of this degree is associated with early degenerative change and is the range in which periacetabular osteotomy is most often considered.
- Borderline dysplasia18–24.9
The 18–25° range is contested. Some of these hips are unstable and behave like dysplasia, others are not; the decision rests on the whole picture including the Tönnis angle, femoral version and the presence of a labral tear.
- Normal acetabular coverage25–39.9
Within the normal range for lateral coverage of the femoral head.
- Acetabular overcoverage40–90
An LCEA of 40° or more indicates overcoverage, associated with pincer-type femoroacetabular impingement. Beyond roughly 40° this may represent coxa profunda or protrusio.
Published criteria and reliability
The published cut-offs that define this instrument, and the measured agreement between observers using it. Each is reported with the population it was derived in.
| Type | Value | Subscale | Population | Follow-up | Source |
|---|---|---|---|---|---|
| Criterion | < 18° — frank acetabular dysplasia | — | Adults, AP pelvis radiograph | — | Wiberg G 1939 |
| Criterion | 18–25° — borderline dysplasia | — | Adults, AP pelvis radiograph | — | Wyles CC 2017 |
| Criterion | 25–39° — normal | — | Adults, AP pelvis radiograph | — | Tönnis D 1987 |
| Criterion | ≥ 40° — overcoverage, associated with pincer impingement | — | Adults, AP pelvis radiograph | — | Tönnis D 1987 |
| Criterion | LCEA below 20° was strongly associated with subsequent hip osteoarthritis | — | Long-term follow-up of dysplastic hips | — | Wyles CC 2017 |
Criterion is a published cut-off, definition or performance figure belonging to a classification or decision rule — it is not a change score and should not be read as one.
How the score is calculated
Stated in full so the calculation can be independently checked, and reproduced by hand if needed.
A vertical reference line is drawn through the centre of the femoral head, perpendicular to a horizontal line joining the inferior aspects of the two teardrops. A second line is drawn from the centre of the femoral head to the lateral edge of the acetabular sourcil. The lateral centre-edge angle is the angle between these two lines. A larger angle means greater lateral coverage of the femoral head.
Instrument profile
- Developer
- Gunnar Wiberg
- Institution
- Karolinska Institute, Stockholm, Sweden
- First published
- 1939
- Items
- 1
- Response format
- Single angular measurement in degrees
- Score range
- 0 to 60
- Direction
- Higher score = better
- Completion time
- About 1 minutes
- Age range
- Adults and skeletally mature adolescents
- Regions
- Hip
- Conditions
- Hip dysplasia, Femoroacetabular impingement, Acetabular undercoverage, Hip instability, Labral tear
- Procedures
- Periacetabular osteotomy, Hip arthroscopy
- Observer agreement
- Interobserver ICC typically 0.86–0.96 when the landmark definition is standardised
- Validity
- The most widely used measure of acetabular coverage, and the parameter on which dysplasia thresholds and periacetabular osteotomy indications are built.
- Reliability
- Reliability is good but depends heavily on radiographic technique and on which lateral landmark is used. Pelvic rotation and tilt both alter the measured angle, and the sourcil and bony-edge definitions can differ by several degrees on the same film.
Normative values
Reference values from published cohorts, for comparison against the score you calculated.
| Population | Age | Mean | SD |
|---|---|---|---|
| Asymptomatic adults | — | 32–36 | 6 |
| Symptomatic dysplasia referred for periacetabular osteotomy | — | 12–18 | — |
When to use the LCEA
Well suited to
- Assessing acetabular coverage in suspected hip dysplasia or femoroacetabular impingement.
- Pre-operative planning for periacetabular osteotomy or hip arthroscopy.
- Screening young adults presenting with hip or groin pain.
Limitations and poor fits
- On a poorly centred or rotated AP pelvis film, where the measurement is unreliable.
- In skeletally immature patients, where the acetabular index is the appropriate measure.
- As a sole assessment of coverage — anterior and posterior coverage need a false-profile view and the posterior wall sign.
LCEA compared with other instruments
Instruments measuring a related construct, with the practical difference between them.
| Instrument | Items | Range | What it adds |
|---|---|---|---|
| Tönnis Angle | 1 | -10–30 | The Tönnis angle measures the slope of the acetabular weight-bearing zone on an anteroposterior pelvis radiograph, where 0 to 10 degrees is normal, above 10 degrees indicates a steep upsloping roof associated with dysplasia and instability, and a negative angle indicates overcoverage. |
| Alpha Angle | 1 | 30–90 | The alpha angle quantifies loss of sphericity at the femoral head-neck junction, the imaging marker of cam-type femoroacetabular impingement, with published thresholds for cam morphology ranging from 50 to 60 degrees depending on the imaging view used. |
| Crowe | 2 | 1–4 | The Crowe classification grades developmental dysplasia of the hip in adults by how far the femoral head has migrated proximally, expressed as a percentage of the femoral head height and estimated from the pelvic height, giving four types: under 50%, 50–75%, 75–100% and over 100% subluxation. |
| HOOS | 40 | 0–100 | The HOOS is a 40-item patient-reported questionnaire that scores hip function as five separate subscales — Symptoms, Pain, Activities of Daily Living, Sport and Recreation, and Hip-related Quality of Life — each from 0 (extreme problems) to 100 (no problems). |
Copyright and permitted use
Published openly because it is the question every clinician and researcher asks before using an instrument, and almost nobody answers it.
A published radiographic measurement method. Freely reproducible; no licence is required.
References
- Wiberg G. Studies on dysplastic acetabula and congenital subluxation of the hip joint with special reference to the complication of osteoarthritis. Acta Chirurgica Scandinavica. 1939.
- Tönnis D. Congenital Dysplasia and Dislocation of the Hip in Children and Adults. Springer-Verlag. 1987.
- Wyles CC, Heidenreich MJ, Jeng J, Larson DR, Trousdale RT, Sierra RJ. The John Charnley Award: redefining the natural history of osteoarthritis in patients with hip dysplasia and impingement. Clinical Orthopaedics and Related Research. 2017.PMID 27830486
Editorial status
This page has not yet been signed off by a named clinical reviewer. The scoring logic is stated in full above so it can be independently verified, and every threshold is traceable to its source. See our editorial methodology.